Reserach And Design Of DNS System Security Enhancement

With the fast development of the globalized net, the number of net citizens isbecoming unprecedentedly big which can not be counted exactly and net citizens hopethat all the network information resources can be shared. However, because of thecharacteristics of sharing and diffusibility of the information, there are the holes in theprocessing, transmitting, storing and using. It is very easy to be disturbed, abused,missed or lost, and even sometimes to be exposed, stolen, distorted, injected, disguisedor destroyed for the information. The safety of network infrastructural facilities andbasic services is becoming more and more important.DNS system is the link of all the network and its safety involves the safety of all thenetwork directly. DNS service develops very fast and its logon scale is becomingbigger and bigger. Thus the management becomes difficult rapidly.Without referring tothe safety at the beginning of designing DNS protocols, various kinds of data on DNSdon’t have encryption protection and certification of prevention and the fragility of theprotocol makes DNS face many kinds of threats.This thesis introduces briefly the DNS systematical structure and working principle,and gives an overview of understanding of DNS. Then it provides an analysis of leakson DNS system and its ways of being attacked, and finds out the reasons why DNS isattacked easily. On the basis of overall analysis of the fragility of DNS, the thesispresents a defense system model that DNS safe guarding can strengthen the survival ofDNS systems.